---
id: CVE-2026-31629
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfc: llcp: add missing return after LLCP_CLOSED checks

  In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket
  state is LLCP_CLOSED, the code correctly calls…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfc: llcp: add missing return after LLCP_CLOSED checks

  In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket
  state is LLCP_CLOSED, the code correctly calls…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-667
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.3, < 6.6.136'
  - 'linux_kernel >= 6.7, < 6.12.83'
  - 'linux_kernel >= 6.13, < 6.18.24'
  - 'linux_kernel >= 6.19, < 6.19.14'
  - 'linux_kernel >= 7.0, < 7.0.1'
patched:
  - linux_kernel 7.0.1
published: '2026-04-24'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:19:13.923'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31629'
references:
  - url: 'https://git.kernel.org/stable/c/0eb1263a3b8c36418c9ba295c9ab3abed664edbf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2b5dd4632966c39da6ba74dbc8689b309065e82c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/665315df9c3486cb213fc44d83cc8bcd47fe0d26'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/796e0cac058252d0ad34ebe288e6f7979b5fc9b2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8977fad2b3c6eefd414131168d597c5d1d5e1abf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9b49e2a4b8219a2fc5cebf94f4ec34e509aff8a6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aba4712e8f0381cd5d196534ce2ad082626a5ab6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b2a23529593d011fb433a3d711fc597ed6a6bd2f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ff3d9e8f7244293e303f7b6ef70774291c7c27e9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-784472.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00351
epssPercentile: 0.27082
ingestedAt: '2026-10-15T03:30:12.861Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

nfc: llcp: add missing return after LLCP_CLOSED checks

In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket
state is LLCP_CLOSED, the code correctly calls release_sock() and
nfc_llcp_sock_put() but fails to return. Execution falls through to
the remainder of the function, which calls release_sock() and
nfc_llcp_sock_put() again. This results in a double release_sock()
and a refcount underflow via double nfc_llcp_sock_put(), leading to
a use-after-free.

Add the missing return statements after the LLCP_CLOSED branches
in both functions to prevent the fall-through.

## Affected

- `linux_kernel >= 3.3, < 6.6.136`
- `linux_kernel >= 6.7, < 6.12.83`
- `linux_kernel >= 6.13, < 6.18.24`
- `linux_kernel >= 6.19, < 6.19.14`
- `linux_kernel >= 7.0, < 7.0.1`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.1`